Shreyas Kher

Bio: Shreyas Kher is an academic researcher from Applied Materials. The author has contributed to research in topics: Layer (electronics) & High-κ dielectric. The author has an hindex of 18, co-authored 35 publications receiving 2446 citations.

Method for hafnium nitride deposition

Abstract: The present invention generally is a method for forming a high-k dielectric layer, comprising depositing a hafnium compound by atomic layer deposition to a substrate, comprising, delivering a hafnium precursor to a surface of the substrate, reacting the hafnium precursor and forming a hafnium containing layer to the surface, delivering a nitrogen precursor to the hafnium containing layer, forming at least one hafnium nitrogen bond and depositing the hafnium compound to the surface.

Plasma treatment of hafnium-containing materials

Abstract: In one embodiment, a method for forming a dielectric material is provided which includes exposing a substrate sequentially to a metal-containing precursor and an oxidizing gas to form metal oxide (e.g., HfO x ) during an ALD process and subsequently exposing the substrate to an inert plasma process and a thermal annealing process. Generally, the metal oxide contains hafnium, tantalum, titanium, aluminum, zirconium, lanthanum or combinations thereof. In one example, the inert plasma process contains argon and is free of nitrogen, while the thermal annealing process contains oxygen. In another example, an ALD process to form a metal oxide includes exposing the substrate sequentially to a metal precursor and an oxidizing gas containing water vapor formed by a catalytic water vapor generator. In an alternative embodiment, a method for forming a dielectric material is provide which includes exposing a substrate to a deposition process to form a metal oxide layer and subsequently exposing the substrate to a nitridation plasma process and a thermal annealing process to form metal oxynitride (e.g., HfO x N y ).

Ald metal oxide deposition process using direct oxidation

Abstract: Embodiments of the invention provide methods for forming hafnium materials, such as oxides and nitrides, by sequentially exposing a substrate to hafnium precursors and active oxygen or nitrogen species (e.g., ozone, oxygen radicals, or nitrogen radicals). The deposited hafnium materials have significantly improved uniformity when deposited by these atomic layer deposition (ALD) processes. In one embodiment, an ALD chamber contains an expanding channel having a bottom surface that is sized and shaped to substantially cover a substrate positioned on a substrate pedestal. During an ALD process for forming hafnium materials, process gases form a vortex flow pattern while passing through the expanding channel and sweep across the substrate surface. The substrate is sequentially exposed to chemical precursors that are pulsed into the process chamber having the vortex flow.

System and method for forming a gate dielectric

Abstract: A method of forming a dielectric stack on a pre-treated surface. The method comprises pre-cleaning a semiconductor wafer to remove native oxide, such as by applying hydroflouric acid to form an HF-last surface, pre-treating the HF-last surface with ozonated deionized water, forming a dielectric stack on the pre-treated surface and providing a flow of NH3 in a process zone surrounding the wafer. Alternately, the method includes pre-treating the HF-last surface with NH3, forming the stack after the pre-treating, and providing a flow of N2 in a process zone surrounding the wafer after the forming. The method also includes pre-treating the HF-last surface using an in-situ steam generation process, forming the stack on the pre-treated surface, and annealing the wafer after the forming. The pre-treating includes providing an inert gas flow in a process zone surrounding the HF-last surface, reacting hydrogen with an oxidizer in the process zone for a very short duration, and providing an inert gas flew in the process zone after the reacting.

Atomic layer deposition processes for non-volatile memory devices

Abstract: Embodiments of the invention provide memory devices and methods for forming memory devices. In one embodiment, a memory device is provided which includes a floating gate polysilicon layer disposed over source/drain regions of a substrate, a silicon oxynitride layer disposed over the floating gate polysilicon layer, a first aluminum oxide layer disposed over the silicon oxynitride layer, a hafnium silicon oxynitride layer disposed over the first aluminum oxide layer, a second aluminum oxide layer disposed over the hafnium silicon oxynitride layer, and a control gate polysilicon layer disposed over the second aluminum oxide layer. In another embodiment, a memory device is provided which includes a control gate polysilicon layer disposed over an inter-poly dielectric stack disposed over a silicon oxide layer disposed over the floating gate polysilicon layer. The inter-poly dielectric stack contains two silicon oxynitride layers separated by a silicon nitride layer.

Semiconductor device, and manufacturing method thereof

Abstract: An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Substrate Processing Apparatus

Abstract: Process gas discharged from a bypass pipe to a gas exhaust system can be prevented from diffusing back to the inside of a process chamber without having to install a dedicated vacuum pump at the downstream side of the bypass pipe. The substrate processing apparatus includes a process chamber accommodating a substrate, a gas supply system supplying process gas from a process gas source to the process chamber for processing the substrate, a gas exhaust system configured to exhaust the process chamber, two or more vacuum pumps installed in series at the gas exhaust system, and a bypass pipe connected between the gas supply system and the gas exhaust system. The most upstream one of the vacuum pumps is a mechanical booster pump, and the bypass pipe is connected between the mechanical booster pump and the rest vacuum pumps located at a downstream side of the mechanical booster pump.

Gas delivery apparatus for atomic layer deposition

Abstract: An apparatus and method for performing a cyclical layer deposition process, such as atomic layer deposition is provided. In one aspect, the apparatus includes a substrate support having a substrate receiving surface, and a chamber lid comprising a tapered passageway extending from a central portion of the chamber lid and a bottom surface extending from the passageway to a peripheral portion of the chamber lid, the bottom surface shaped and sized to substantially cover the substrate receiving surface. The apparatus also includes one or more valves coupled to the gradually expanding channel, and one or more gas sources coupled to each valve.

Sequential deposition/anneal film densification method

Abstract: A silicon dioxide-based dielectric layer is formed on a substrate surface by a sequential deposition/anneal technique. The deposited layer thickness is insufficient to prevent substantially complete penetration of annealing process agents into the layer and migration of water out of the layer. The dielectric layer is then annealed, ideally at a moderate temperature, to remove water and thereby fully densify the film. The deposition and anneal processes are then repeated until a desired dielectric film thickness is achieved.

Apparatus and process for plasma-enhanced atomic layer deposition

Abstract: Embodiments of the invention provide an apparatus configured to form a material during an atomic layer deposition (ALD) process, such as a plasma-enhanced ALD (PE-ALD) process. In one embodiment, a lid assembly for conducting a vapor deposition process within a process chamber is provided which includes an insulation cap and a plasma screen. In one example, the insulation cap has a centralized channel configured to flow a first process gas from an upper surface to an expanded channel and an outer channel configured to flow a second process gas from an upper surface to a groove which is encircling the expanded channel. In one example, the plasma screen has an upper surface containing an inner area with a plurality of holes and an outer area with a plurality of slots. The insulation cap may be positioned on top of the plasma screen to form a centralized gas region with the expanded channel and a circular gas region with the groove.